A mobile communication device, also referred to as a user equipment (UE), e.g. a mobile phone, comprises a receiver for receiving a communication signal of a base station, such as a 2G-signal, also called a GSM-signal (global system for mobile communication), or a 3G-signal, also called a UMTS-signal (universal mobile telecommunications system). Such communication systems, like a GSM-system or a UMTS-system, use multiple carriers for transmitting information content to multiple receivers, respectively. The receiver of a mobile communication device is configured to receive a communication signal dedicated to the respective mobile communication device via one or more carriers. In order to receive the wanted signal carrier, a filter is used to separate same from, for example, other carriers.
For UMTS-communication-systems, for example, the typical carrier spacing between 3G frequencies is 5 MHz. A guard band between two adjacent carriers is provided. If the guard band between the wanted carrier and an adjacent carrier is set too small, interferences between the wanted carrier and a neighboring carrier may be caused. The result of this interference is a degradation of the signal-to-noise-ratio (SNR) performance.